In a manufacturing process of a color filter substrate (CF process) for a thin film transistor liquid crystal display (TFT-LCD) device, a coating device is disposed at a second stage of a production line and mainly used for coating a photoresist (PR) onto a substrate surface so as to form a film thereon. When switching between different PRs, or, in order to ensure a quality of the CF process, it may need to clean an inside of a nozzle of the coating device on demands or at regular intervals, so as to remove PR and/or other impurities remaining inside the nozzle. The film forming process is a foundation of the entire CF process, while a nozzle cleaning operation is the key point for ensuring a coating effect.
Existing coating devices for the CF process are all cleaned manually, for example, by an operator who holds a cleaning piece at hands and enters the inside of the coating device for nozzle cleaning. It's not only a waste of time and labor, but is also likely to cause quality issues, thereby resulting in more shut-down periods due to differences in cleaning operations which are varied depending on the operator. Moreover, the operator who enters the inside of the coating device may bring in foreign matters such as dusts and particles. In addition, dealing with PR glues or PR solutions for long time may also affect human health, more or less.